Back then in 2015 Microsoft signed a partnership with the China Electronics Technology Group (CTEC) to develop a custom version of Windows Operating System. This was to served special orginazation and the Chinese government. This is interesting especially if we know that the Chinese governement banned Windows 8 back then.
CETC, as one of China’s large-scale state-owned high-tech enterprise groups, has been leading China’s electronic information technology innovation over the past sixty years. CETC is devoted to providing information products, services and complete solutions of high competence to customers. -Microsoft
The Chinese government has always been concerned about using the foreign software. They assume that such software could be used by the NSA to spy on them.
Today, according to The Verge, that version is ready.